Piston



May 23? 193.9 .c RETscHY 2,159,402 w PIsToN Filed Feb. l; 1939 7% l f /4 7\ 7721/17?! 15E Z0 7v J 23 4 20 i 'l 24 /3 y Lgf-A3' Y. I 3

AIiate'vnted May 23A, 1939- miran ASTATES 'PATENT OFFICE 2.15am i our: mushy, winterthur, switzerland, namur to Sulzer Fueron-Socit Anonyme, Winterthnr, ASwitlaeriand.

1o claim. (ci. ias-193) This invention relates to a piston primarily intended for use yin an internal combustion engine. In the particular form shown, the piston is not cooled by any positive cooling means.

5 invention has for one object to provide in a piston construction means'for resisting high heat and for conducting and 4dissipatingthat heat. Another object is to provide a built-up piston y construction in which the several parts are so joined.together as to resist distortion. A still further object is to provide a built-up piston in whichthe several parts are so shaped and joined together as to provide an adequate path for the The' transfer of the heat from the zone of combustion. 1

Another object is to provide a piston made of a number of parts so arranged that they are positively secured together along the piston axis orv l along lines parallel vwith'that axisand are relatively free for relative radial motion.

Other objects will appear from time to timev throughout the specification and the claims.

'Ihe invention is illustrated more or less diagrammatically in the accompanying drawing',

wherein: Figure 1 is aulongitudinal sectiony through the piston and a portion of the engine cylinder; Y

Figure 2 in its left hand is a'top plan view ofthe plate'which forms the upper surface of' the piston, and in its right'hand section is a 3'0 bottomplan view;

Figure 3 is a top plan view ofthe or bell. ,Y r

throughout the speciflcation'and the drawing.

, I indicates a portion of a cylinder wall.v A liner 2 is positioned therewith. A cylinderhead 3 is mounted upon the liner and delines in part the combustion chamber. A ring-like member l -is'positioned outside of the cylinder head 3 and is 40, securedinnposition upon the \cylinder jacket I by nuts and bolts 5 or by screws or `otherwise.

A 5 are cooling spaces formed'inthe cylinder-head and` 1 are coolingspaces lformed between'thev u types of'enginesand in fact a piston of the type piston body Like'partjsf are designated by like characters "I2 and Vthe'core I5 together, a central bolt IG is here shown may be used in many places where, it is desirable or necessary to provide for the resistance of the piston to heat and to provide for the dissipation of heat from the piston. 'Ihe use of the present invention is,therefore, not 5 limited to an engine. l

'Ihe main upper surface of the piston is formed by a highly heat-resistant plate II, which overlies substantially the whole surface of the piston with the exception of that which is defined by l0 the ring-like member III, which is shaped to overlie and in part to, support the uppermost piston p ring. Themain piston body or bell comprises a member I2 having a depending integral skirt I3, within which is positioned a number of piston rings Il. As above mentioned, the uppermost of the piston rings is in contact with the member Il).

Positioned within the hollow deiined by the piston face I2 andthe skirt I3 is a core I5 of material having high heat conductivity. One suitable material is aluminum. This core serves to conduct heat from the plate I I to the member I2 and thence to the skirt I3.

As a means of securing the plate I I, the piston 25 used.- It may be threaded at its upper end as at I1 to engage ,'a correspondingly 'threaded socket or' depression II--a on the underl side-of tlisefplate 4'II'.-.At its outer end the bolt"v I6 is threaded to receive a nut I9, which holds the parts together and in the particular form here fshownwcontacts a washer or ring I 9 positioned against or seated within a suitable depression in As shownn Figurel, the parts illustrate the condition when cold and it will be seen that there is a clearance '2li between the core I5 and the `skirt Il. 'I'he parts are free for relative radial movement, 'whicnwill :occur on expansion and contraction, and the core I5 cannot transmit heat directly to the skirt Il until it has expandedk sumciently under the influence of heat to come into contact with the skirt. y

As a further means for holding the parts generally in suitable position, a number of attaching bolts 2| is provided. These bolts serve merely the'purpose of holding the surface plate II to the portion -I1 of the piston. Clearance-y is provided between the bolts and the member I2.. A number of additional and longer bolts 22 is also provided and these secure the core I5 in position within the piston I2. Clearance y is provided about the bolts 22 just as it is provided about the bolts 2|. A spacing sleeve 23 is provided about the bolts 2l and is of material preferably more or less self-lubricating. Nutsf2l are positioned upon the bo1ts2l. A sleeve 23d of similar materialis provided about the lbolts'22, and

,nuts u -a secure the nous 'and the sleeves in proper position. In general, the bolts 2|v and 22 f hold the plate-II, inplaoe and prevent its distortion when it is'heated. In particular; they prevent buckling or 'warping-of this plate, but

because of the play between them and the portion I2 of the piston and between them and the core I5 A,they permit radial movement of the parts, one with relation to the other".

1 example, are turned on only by hand and thus' gg the opposing faces of both the member 1I I and the member I 2.

The nuts 24, for

'I'he remainder ofthe piston and connecting y rod construction need not be shown. In general, they may comprise a ring-like portion 26, which is held in place in the piston assembly by'the bolts 22; and they may vinclude other parts 21, shown only in part, and th necessary bearings 'and bearing supports for connection to the connecting rod. 'I'heseparts are omitted because they'iorm no essential part'of the present invention and are not necessary for an ing ofit.

Although I have shown an operative form of my device, it will b e understood that many changes in the form, shape and arrangement of parts might be made without departing from the spirit of my invention, and IA wish that my showing betaken as in a sense diagrammatic.

The'use and operation of this invention are as follows:

The piston may be used in anyplace where it is desirable to havel a piston so arrangedthat it can dissipate heat adehuately and without dis. tortion.v As shown, it is applied to an intern lcombustion engine of the injection type.

and already described, and these are secured to.

gether as shown. The piston is positioned in'a cylinderand is secured to 'a connecting rod in any `desired manner.

piston is cold, the partsare tosome degree reduced in size to provide the' ciearanceskshown. As heat develops in the use of the engine', a 4certain amount of expansion occurs. 'Ihe heat'ilrst affects the main piston bell I2, heat is conducted from the plate to the bell only alongthese limited paths Y of contact. In tlie particular form sl'own,4 these paths are largely defined by the raised portions understandf In the. association shown herewith, whenlthe' highly heat-conductive material1 positioned with- 'I'he piston is formed of the several parts shown .i

25 of the upper surface of the bell I2. Some heat will, of course, be conducted through the ntl'l bOlt ls and 8180 through the bolts 2 The upper surfaces ofthe bolts are, as shown in Fig-- ure l, shaped to provide the same general sort of of the members which y in contactv with each other/and are carrying their vescasos Because the plate and the bell and the core 'I5 are connected only on the line of the piston axis, they are freed for relative radialmovement, which occurs, of course, on expansion and contraction of one or another of these parts.

- Heat received by the plate II and conducted through the members 25 to the u pper surface of the bell I2 is then conducted by direct contact to the c'ore I5; and because the core is ordinarily in contact with the piston skirt I3 when the parts are fully heated, heat from the core is transmitted directly to the skirt of thepiston.

Shouldl any tendency toward buckling develop in any of the parts, and particularly in the plate I'I that tendency is resisted by the bolts 2 I which prevent buckling. They are ordinarily screwed in only lightly-as, for example, by hand-and they lare also provided with the lubricating or sliding sleeves 23 so that they freely carry the thrust of the plate and, therefore, hold the plate free for radial expansionand vcontraction while preventing buckling.

lIn use, becauseof the construction shown, the i heatprotecting pme; [is raised to a sufficient v temperature largely because the heat'dissipated from the plate II must pass through thelimited contact `members 25;;{iandthe heat dissipation from the plate II tothe Aother parts of the builtup piston is thus slower than it would be if the parts were all in ful lg contact with each other.

. Because of the limited contact between the plate I I and the bell I2, las the plate I.I is heated from above during engine operation, there occurs at first from the plate II downwardly only an axial heating current or flow. As the parts expand under the influence of heat, additional contacts occur between the various parts, and the path through which theheat flows is increased by these added contacts. This process continues until all rnake up the piston are loads uniformly.-

I claim:

l. In combination in a built-up piston, a main piston bell having an outer end member and a skirt, a separate surface 'member of highly heat-resistant material positioned onthe outer end of said vpiston and deilningthe outer end surface of the .,piston, and a .core member of in the said piston, and means for 'securing the three together in heat transfer relation, said -means permitting relative. radial movement o f 2. In combination in a built-uo piston, a main piston bell vhaving an outer end member and a means permitting relative radial Amovement of` the three and preventing their axial separation. 3. In combinationin a piston comprising a main bell member, having an end member and a skirt,` a heat protecting surface plate attached to said piston positioned above the surfacel of its en d member, and means positioned between the opposing surfaces of the piston and the plate .adapted to hold them largely out of contact, the said means comprising the sole contact between the said two surfaces, and an attachment 1.5 limited contact with the heat-resistant plate II. joining' the the piston together. said attachment adapted -to permit relative radial Vmovement ofthe two.

4. In combination in a piston comprising a main bell member, having an end member andA a skirt, a surface plate attached to said piston y positioned above thesurface of its end member,

and means positioned between the opposing surfaces of the piston and the plate adapted to hold them largely out of contact, the said means comprising the sole contact between the said two surfaces, Aand anlattachment joining the plate and the piston together, said attachment adapted to' permit relative radial movement of the two and adapted to tion. l

5. In combination in a piston comprising a main bell member, having an end member and a hold them against axial separa= skirt, a surface plate attached to said piston positioned above the surface of itsjend member, -'and' formed of highly heat-resistant material, and means positioned between the opposing surfaces of the piston and the plate adapted to hold them largely out of' contact, .the said means comprising the sole contact ,between the said two surfaces, and an 'attachment joining the plate and the piston together, saidattachment adapted to permit relative radial move- .ment of the two. f

6. In combination in a piston comprising a main bell member, having an end member and a skirt, a. surface plate attached to said piston positioned above the surface of its end member and formed of highly heat-resistant material, and means positioned between the opposing surfaces of the piston and the plate adapted to hold them largely out of contact, the said means com--A prising 'the sole contact between the said two surfaces, and an attachment 'joining the plate Aand the piston together, said attachment adapted to permit relative radial movement of the two and adapted to hold them against axial separation.

. 7. lIn, combination in a. built-up piston, a piston bell, a' plate positioned on the outer face of the piston and formed of highly heat-resistant material, a core positioned within the bell and formed of highly heat-conductive material, and

means positioned between the plate and the upper surface of the bell to limit the contact of the two to an area appreciably lessthan their total opposed areas. y

8. In combination in a built-up piston, .a piston bell, a plate positioned on the outer'face of the piston and formed of highly heat-'resistant material, a core positionedwithin the bell and formed of highly heat-conductive material, and means positioned between the plate and the upper surface of the bell to limit vthecontact of thetwo to an area appreciably less than their total opposed areas, and fastening means joining` the several parts to each other and adapted to hold the parts against relative longitudinal movement 4but to permit relative radial movement of the parts.

9. In combination in a piston, a piston bell having a top plate and a downwardly depending skirt integral therewith, a heat-resistant plate positioned above and supported upon said piston bell, a core formed of a highly heat-conductive material positioned within said piston, and means positioned approximately on the line of the longitudinal axis of said piston, said means securing .the plate, the piston bell and -the coretogether; the piston bell being provided in' its outer surface with a number ofraised members, additional attaching means, some engaging said plate and holding it to the upper surface of said bell and others engaging said bell and holding said core in place, the parts being 

